Time indicator for a timepiece

ABSTRACT

A time indicator for use in a timepiece having two rotationally driven hour and minute disc indicators having a non-circular central aperture about a driving element having a complementary non-circular cross section. The driving elements have heads with tapered lower surfaces making it easy to remove the driving elements from their driving hour and minute shafts. The central apertures of the disc indicators receive the driving elements with a slight interference for ease of assembly and disassembly.

United States Patent 1191 Masui Nov. 12, 1974 [54] TIME INDICATOR FOR A TIMEP'ECE FOREIGN PATENTS OR APPLICATIONS 1' lnvemorl Yasllyuki Masui y Japan 305,461 2/1955 Switzerland 58/126 A [73] Assignee: Kabushiki Kaisha Daini Seikosha,

T k Japan Primary Egaminen-EeorggHB Milllzcrlr. Attorne ent, or irm- 0 ert urns; [22] Med: 1974 Emmaniiel Lobato; Bruce L. Adams [21] Appl. No.: 445,240

A [57 ABSTRACT 2 [30] Foreign Application Priority Data A time indicator for use in a timepiece having two ro- Feb. 28, 1973 Japan 48-25253 tationally and minute disc indicators ing a non-circular central aperture about a driving ele- 52 U.S. c1 58/126 A merit having a comPlememaiy "On-Circular cross 511 1m. 01. G04b 19/00 tion- The driving elements have heads with tapered [58] Field Of Search 58/125 B, 126 R, 126 A, lower Surfaces making it y to remove the driving 5 7 R 7 B, 128 elements from their driving hour and minute shafts. The central apertures of the disc indicators receive the 5 k f cit d driving elements with a slight interference for ease of UNITED STATES PATENTS assembly and disassembly.

7 Claims, 6 Drawing Figures PATENT-ED HEY I 21924 TIME INDICATOR INDICATOR INDICATOR MINUTE DISC DIAL WATCH MOVEMENT F/G. (PR/ R ART) III 4B1 HIHHH I!!! FIG. 2

FIG. 3 FIGS]; H6317 FIG. 3

1 TIME INDICATOR FOR A TIMEPIECE BACKGROUND OF THE INVENTION This invention relates generally to timepieces and more particularly to a time indicator for use in timepieces.

Timepieces in which the time indicators comprise a plurality of driven time-indicating discs are known. These known time indicatorsare mounted on the hour and minute shafts of a timepiece but are very hard to remove therefrom when servicing a timepiece. The removal is sufficiently complex that jigs and tools are not available for removal andspecial tools are required; breaking of the tools or the indicator dicss is a fairly common occurrence.

SUMMARY OF THE INVENTION It is a principal object of the present invention to provide a new and improved time indicator easily assembled and worked on.

Another object is to provide a time indicator on which the time indicator discs are freely mounted for easy removal.

Time indicators according to the invention comprise two driven disc indicators each having a non-circular central aperture. One of the disc indicators is an hour disc indicator and another of the disc indicators is a minute disc indicator. The two discs are driven by an hour and a minute driven shaft. Each shaft has a noncircular cross section driving element and support for driving a corresponding disc indicator. The noncircular aperture of each disc indicator is complementary to the non-circular cross section of a corresponding driving element and fits freely thereon with a slight interference. Each disc can thus be easily removed. The driving elements have lower tapered surfaces engageable with a tool for removal of the driving elements from the hour and minute shafts.

BRIEF DESCRIPTION OF. THE DRAWINGS DESCRIPTION OF A PREFERRED EMBODIMENT As shown in FIG. 1 a timepiece dial with time indicia thereon is mounted on a timepiece movement driving an hour shaft and a minute shafton which respective hour and minute disc indicators are mounted and secured thereto by a central washer press fitted on the respectiveshafts. In order to remove the disc indicators considerable trouble is encountered in inserting special jigs or tools in narrow spaces A, B between the disc indicators. Thus in servicing the known time indicators considerable trouble and disc breakage is encountered.

According to the drawings a time indicator according to the invention usable in Wristwatches comprise a dial 1 having time indicia thereon. A washer 2 is mounted thereon and functions to rotatably support an hour disc indicator 3 centrally of which is disposed a driving support member 4 that has an upper flange on which is rotatably supported a minute disc indicator 5. Both the disc indicators are made of transparent material, for example plastic and have indicia thereon for indicating time in conjunction with the dial 1. An upper driving element 6 is supported for rotation relative to the other or lower driving and support element 4. The lower driving and support element 4 is driven by an hour shaft 7 and the upper driving element by a minute shaft 8 on which they are removably mounted. The driving elements 4, 6 have a non-circular cross section in an axle part thereof which may correspond to any of the configurations in FIGS. 31 to SW for driving the related disc indicators 3, 5. The disc indicators 3, 5 have central apertures 3a, 5a which are non-circular and fit with a slight interference on the axle part of its driving element 4, 6. The central apertures of the disc indicators are complementary to the cross section of the axle portions of the driving elements and accordingly have a shape corresponding to any of the configurations shown in FIGS. 3I to 31V.

The hour and minute shafts 7, 8 are driven by a watch movement 9 to which is connected a winding stem 10.

thereunder for removing the heads from the driving shafts and the disc indicators mounted freely thereon a when servicing the time indicator.

The time indicator is an assembled unit of the components described. In assemblying it, the dial 1 is mounted on the watch movement and the washer 2 is disposed circumferentially of the driven hour and minute shafts. The washer 2 is well secured or otherwise bonded to the dial 1. The hour disc 2 is disposed on the bearing washer 2 and its central aperture 3a freely, but with some interference, receives the support and driving element 4 which is fixed to the hour shaft 7. The support and driving element has the minute disc indicator 3 supported thereon and its central aperture 3a receives the driving element 6, with some interference, which is fixed to the minute shaft 8.

In removing the disc indicators 3, 5 from the driven shafts 7, 8, the minute disc indicator 5 is first removed from the minute shaft 8 by inserting the tip of a too] between the inclined surface 6b forrned on the minute disc support 6 and the minute disc indicator 5 and raising the tool to remove the driving and support element 6 from the shaft 8. Next the hour disc support and driving element 4 is removed from the hour shaft 7 byinserting the tip of a tool between the inclined surface 4b of the hour disc indicator 3 and raising the support element 4.

Those skilled in the art will understand the ease of assembly of a time indicator according to the invention and the facility with which it can be serviced. The disc indicators may be provided with patterns of humorous material and a very interesting watch will be provided because the relative positions of the hour and minute disc indicators varies with time. The use'of a polariger full application thereof.

I claim:

1. Time indicator for use in a timepiece comprising two transparent driven discdndicators each having a non-circular central aperture, one of said disc indicators comprising an hour disc indicator and another of said disc indicators comprising a minute disc indicator, first driving means driving said hour disc indicator comprising a driven hour shaft and a first driving element on said hour shaft, said first driving element on said hour shaft having a non-circular cross section and a support surface, said another disc indicator comprising a minute disc indicator resting on said support surface of said first driving element for relative rotation thereon, second driving means driving said minute disc indicator comprising a driven minute shaft coaxial with said hour shaft and a second driving element on said minute shaft, said second driving element having a noncircular cross section, said hour and minute disc indicators each having a non-circular central aperture receiving the corresponding first and second driving elements, said apertures being complementary with the cross section of said corresponding driving elements.

2. Time indicator for use in a timepiece according to claim 1, in which said first and second driving elements have a head portion having a tapered lower surface for receiving a tool thereon for removal from a corresponding driven shaft.

3. Time indicator for use in a timepiece according to claim 1, wherein each non-circular aperture includes two parallel sides.

4. Time indicator for use in a timepiece according to claim 1, wherein each non-circular aperture includes two parallel sides joined by arcuate sides.

5. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is square.

6. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is hexagonal.

7. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is triangular. i 

1. Time indicator for use in a timepiece comprising two transparent driven disc indicators each having a non-circular central aperture, one of said disc indicators comprising an hour disc indicator and another of said disc indicators comprising a minute disc indicator, first driving means driving said hour disc indicator comprising a driven hour shaft and a first driving element on said hour shaft, said first driving element on said hour shaft having a non-circular cross section and a support surface, said another disc indicator cOmprising a minute disc indicator resting on said support surface of said first driving element for relative rotation thereon, second driving means driving said minute disc indicator comprising a driven minute shaft coaxial with said hour shaft and a second driving element on said minute shaft, said second driving element having a noncircular cross section, said hour and minute disc indicators each having a non-circular central aperture receiving the corresponding first and second driving elements, said apertures being complementary with the cross section of said corresponding driving elements.
 2. Time indicator for use in a timepiece according to claim 1, in which said first and second driving elements have a head portion having a tapered lower surface for receiving a tool thereon for removal from a corresponding driven shaft.
 3. Time indicator for use in a timepiece according to claim 1, wherein each non-circular aperture includes two parallel sides.
 4. Time indicator for use in a timepiece according to claim 1, wherein each non-circular aperture includes two parallel sides joined by arcuate sides.
 5. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is square.
 6. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is hexagonal.
 7. Time indicator for use in a timepiece according to claim 1, in which each non-circular aperture is triangular. 